In U.S. Pat. No. 3,627,192, owned by the assignee of this application, there is described a wire bonding tool of the capillary or wedge type including a shank of a material having a high modulus of elasticity such as tungsten carbide with one end portion forming a bonding tip. A wire guiding hole machined into the tip presents the wire to be bonded to the tip. The end portion of the tool is made of an osmium alloy to provide an improved bond and increased tool life.
In U.S. Pat. No. 3,971,499, owned by the assignee of the present application, there is described a bonding wedge tool for joining or bonding wire leads to contact areas or elements in the semiconductor and electronic industry including a rectangular wire guiding hole extending therethrough cooperating with a positioning groove formed on the bonding tip.
In many applications in the semiconductor and electronic industry where lower impedance, higher thermal conductivity, lower electrical resistance and increased mechanical strength is required for interconnecting, a rectangular wire or ribbon is preferred over round wire. As devices decrease in size the lead pitch, spacing between leads, is reduced. There is a need for a bonding tool or wedge capable of handling fine ribbon. There is also a need for a bonding tool in which guiding holes need not be formed in the bonding tip to direct the wire. As used herein, wire includes wire of rounded cross-section or wire of rectangular cross-section (ribbon).